The present disclosure relates to a semiconductor structure, and particularly to a semiconductor structure from which semiconductor growth defects are avoided, and a method of manufacturing the same.
Selective epitaxial deposition of semiconductor materials can be employed to add semiconductor materials only on pre-existing semiconductor surfaces while avoiding deposition of the semiconductor materials on dielectric surfaces. Selective epitaxial deposition processes can be advantageously employed, for example, to form raised source regions and raised drain regions on field effect transistors.
Deposition of a semiconductor occurs on all physically exposed semiconductor surfaces during a selective semiconductor deposition process. Accidental physical exposure of a semiconductor surface that should be protected with an overlying dielectric material during a selective epitaxial deposition process induces unwanted deposition of the semiconductor material on the accidentally exposed semiconductor surface. Such accidental physical exposure of a semiconductor surface may occur due to run-to-run process variations, within-wafer non-uniformity of an etch process, and/or due to loading effect of an etch process that tends to remove more material in isolated structures or peripheral structures than in an array environment.
Such unwanted deposition of the semiconductor material induces formation of semiconductor material portions that are grown on an underlying semiconductor surface, which are herein referred to as semiconductor growth defects. In cases where prevention of semiconductor growth defects is not practicable, methods for removing such semiconductor growth defects are desired.